Restoration recommendations for mitigating habitat fragmentation of a river corridor

Pin-Han Kuo; Shang-Shu Shih; Marinus L Otte

doi:10.1016/j.jenvman.2021.113197

Restoration recommendations for mitigating habitat fragmentation of a river corridor

J Environ Manage. 2021 Oct 15:296:113197. doi: 10.1016/j.jenvman.2021.113197. Epub 2021 Jul 15.

Authors

Pin-Han Kuo¹, Shang-Shu Shih², Marinus L Otte³

Affiliations

¹ Department of Civil Engineering, National Ilan University, Ilan City, 260, Taiwan.
² Department of Civil Engineering, National Taiwan University, Taipei City, 106, Taiwan; Hydrotech Research Institute, National Taiwan University, Taipei City, 106, Taiwan. Electronic address: uptreeshih@ntu.edu.tw.
³ Wet Ecosystem Research Group, Department of Biological Sciences, North Dakota State University, 201 Stevens Hall, Fargo, ND, USA.

PMID: 34274615
DOI: 10.1016/j.jenvman.2021.113197

Abstract

Flow discharge and anthropogenic activities influence the composition and configuration of habitat patches in river ecosystems. Understanding the response of habitat landscapes and the corresponding fish habitat quality is crucial for river management. We investigated the reaction of fish habitat suitability and variant flow discharge performance in examining aquatic habitat patch fragmentation. The hydraulic simulation and fish habitat calculation were used to determine the flow characteristics, habitat conditions, and river landscapes. FRAGSTATS was applied to explore the composition and configuration of habitat patches. Cluster analysis and logistic regression were employed to compute the spatiotemporal variabilities of riverscape indices and establish the relationship between riverscape attributes and fish habitat quality. The results indicate that the changes in specific habitat features are associated with the riverscape indices of total edge (TE), mean nearest-neighbor distance (MNN), interspersion and juxtaposition index (IJI), mean patch size (MPS), and area-weighted mean patch fractal dimension (AWMPFD). The flow discharge is the key to determining habitat fragmentation in rivers, with natural barriers occurring at low flow. In contrast, weirs are anthropogenic obstacles that have significant adverse effects on the downstream corridor. A priority restoration activity to conserve river habitat is to create refuge pools during dry seasons by modifying channel morphology. The positive correlation between habitat suitability and MPS and the negative relationship between habitat suitability and AWMPFD highlight the patch size and shape complexity that are critical indices for pool creation. The prediction of the landscape attributes of the outcomes under different scenarios could support the decision-making in river management. The innovative integrated method presented in this study provides a solid foundation and supports the implementation of nature-based solutions for sustainable river management.

Keywords: Fish habitat; Flow discharge; River corridor; River management; Riverscape.

MeSH terms

Animals
Ecosystem*
Fishes
Rivers*
Seasons